1. Field of the Invention
Exemplary embodiments of the present invention relate to cargo container tracking, and more particularly to the use of a low-rate personal area network system for tracking containers.
2. Description of Background
The fragmentation of the logistics industry makes it nearly impossible to track shipments continually from the manufacturer to the shelf. This because many of the current logistics involved in the shipping of packaged merchandise involve enormous levels of complexity, dated processes that generate lengthy paper trails, and limited levels of traceability and security. Information gaps arise, creating delays, high costs, and a limited ability to secure cargo throughout the entire supply chain. Moreover, security experts have warned of doomsday scenarios involving unchecked containers that may harbor terrorists, explosives, or other hazardous materials. As a result, improving the quality of container tracking for packaged merchandise in transit across trade lanes and improving the security of transported goods in global supply chain operations are increasingly being investigated in the effort to enable globally integrated business practices.
While container tracking has traditionally been performed passively, active tracking units, such as IBM's TREC (Tamper-Resistant Embedded Controllers) or FELA's CarLoc system, are still relatively new. TREC is a technology utilizing intelligent real-time tracking devices that are fitted to cargo containers and designed to withstand the environment they operate in. Unlike typical passive tags that collect data only, the wireless TREC devices incorporate significant processing power, enabling them to instantly receive and send data. The devices automatically collect information on each container, such as physical location based on its built-in global positioning system (GPS), environmental parameters such as temperature, air pressure, and humidity, and sensory readings such as shock or acceleration to detect intrusion. With its built-in GPS, a TREC device can be used to create a complete location history and alert in virtual real-time when a shipment strays from its planned route.
A fundamental problem for these emerging tracking devices is power-efficiency because these devices can only be powered by batteries or accumulators for dry good containers. To lengthen the service cycles of such devices and their power sources, power consumption must be kept to a minimum. In attempting to achieve this, it is important that certain transitions in a container's journey be detected. In particular, the loading of the container onto departing ocean-bound vessels is of interest because, during the ocean leg of a trade lane, there is a reduced security risk, the location of the container is known (on the vessel), and the tracking device is idle because it is not able to easily communicate using terrestrial or satellite communication. As a result, the tracking device can be operated in a low-power sleep or stand-by mode to prolong battery life. Accordingly, it is desirable to provide a mechanism for container load detection that is accurate, reliability, and becomes detectable on the vessel onto which a given container is loaded.